1. Field of the Invention
This invention relates to the use of lightweight, waterproof and airtight thermoplastic material in film form, as a protective package.
2. Description of the Prior Art
Conventional packaging materials include notably a pre-inflated material known as "bubble pack." Bubble-pack, made by Sealed Air Corporation, consists of two layers of thin plastic material such as polyethylene or vinyl formed with random bubbles between the layers and filled with air at time of manufacture, thereby requiring large rolls of bubble material that displace a great deal of volume in trucks, rail cars and in storage before use.
Conventional packaging materials such as pre-inflated bubble-pack are bulky and therefore expensive to ship to a user of the materials and to store during the period before they are put to use. Moreover, conventional packaging materials such as bubble-pack provide limited protection in certain applications because of the fixed bubble diameter, height and count in a given material area.
Daniel A. Pharo has pioneered and patented several improvements in inflatable packaging devices. His patents include:
U.S. Pat. No. 4,597,244, dated Jul. 1, 1986 for "METHOD FOR FORMING AN INFLATED WRAPPING"; PA1 U.S. Pat. No. 4,793,123, dated Dec. 27, 1988 for "ROLLED-UP PACKAGING SYSTEM AND METHOD"; PA1 U.S. Pat. No. 4,872,558, dated Oct. 10, 1989 for "BAG-IN-BAG PACKAGING SYSTEM"; PA1 U.S. Pat. No. 4,874,093, dated Oct. 17, 1989 for "CLAM-LIKE PACKAGING SYSTEM"; PA1 U.S. Pat. No. 4,918,904, dated Apr. 24, 1990 for "METHOD FOR FORMING CLAM-LIKE PACKAGING SYSTEM"; PA1 U.S. Pat. No. 4,949,530, dated Aug. 21, 1990 for "METHOD FOR FORMING BAG-IN-BAG PACKAGING SYSTEM";
The disclosures of the patents cited above are incorporated herein by reference. In addition, there are several patent applications of Pharo pending within the same field.
Pharo's prior patents involve distinct, separate pouches or bags that are manufactured automatically, one or more at a time, from two or more plies. In the case of a four-ply bag, the Pharo patents disclose the use of inflation air chambers and isolation of the; inflation air from the inner chamber, thereby shrinking and locking a product in the center of the four-ply bag with a total air cushion around the product. The unique valving and air transfer system disclosed in the prior Pharo patents enable the filling of the outer bag and shrinking of the center bag.
A common limitation of the bags disclosed in the prior Pharo patents is that each bag has a fixed size or dimension before filling with air.